There are actually different cinnamons. Ceylon cinnamon is the true cinnamon and is typically more expensive than the other cinnamons (called cassia cinnamons) that are more commonly used. The big difference between them is that cassia cinnamons have higher levels of coumarins compared to the Ceylon cinnamon. The anti-coagulant properties of coumarins does not cause a problem when ingesting Ceyon cinnamon, but can become dangerous when ingesting the cassia cinnamons, if consumed in large amounts on a regular basis. This is especially dangerous for someone who is on blood-thinning medication!
OK. So how do you tell them apart? Click here for a wonderful explanation about the differences and click here for a visual way to tell them apart. Then, if you decide to consume cinnamon on a daily basis, make sure you get Ceylon cinnamon from now on.